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Re: Lithium batteries at change out time
Reply #25
Yahoo Message Number: 156597
When I replaced the two fried AGMs with a new pair in June of this year, I also replaced the HPV-22B charge controller with a Blue Sky 3000i; the original Parallax converter had been replaced with a 45A Progressive Dynamics 4600 "kit" earlier.

http://www.progressivedyn.com/pd4600_converter_replacement.html

A discussion with Greg Holder at AM Solar appeared to confirm what I had suspected, i.e., that the AGMs installed in 2010 had very likely been consistently overcharged. The 3000i is reputed to be a lot "smarter" than the HPV-22B and the voltages are set for appropriate charging of the new AGMs. After a few months, the trio of AGMs, 3000i, and PD "Inteli-power" multi-stage converter appear to be playing well together with 300W of panels.

Developments in solar and battery technology move forward quickly, and more is learned about the real life behaviors and requirements of batteries and the corollary systems every day; a lot of what was thought to be "state of the art" five years ago isn't even available now.  From my experience, I believe that an appropriate battery-charge controller "match" is critical to optimum performance and battery (AGM or flooded-cell) longevity.

Joan
2003 TK has a new home

Re: Lithium batteries at change out time
Reply #26
Yahoo Message Number: 156598
My batteries are AGM's.  Why?  First, I have 6 of them.  The only place they fit is inside.  Second, as the AGM's don't vent, the terminals are less likely to experience corrosion.
 For me, there is one aspect (stored inside) that mandates AGM's.  In consideration of the other factors - reduced need for monitoring, checking levels, reduced corrosion, I think I might have paid 50% more for AGM's even if they were outside.  I have seen too many rotting battery trays and mounting brackets that were damaged by acid to expect conventional batteries to remain trouble-free, like my AGM's.  Would I pay 450% more for Lithium Ion, assuming the $1900 vs $400 is correct?  Probably not, though they have a lot of appeal to me.  Maybe when my AGM's, now 7 years old, begin to show signs of age, Lithium Ion batteries may be more cost-competitive.

Ken F in NM
'08 MB

Re: Lithium batteries at change out time
Reply #27
Yahoo Message Number: 156602
AGM has some  advantages over lead acid.  Biggest problem with is folks after reading about the advantages of a AGM just remove the lead acid batteries and replace them with a  AGM set.   AGM's need a different changing regulator.  AGM's are sensitive to over charging.  Generaly lead acid charging systems have a fixed voltage setting at 14.4v or 2.4v per cell.  This leads to overcharging a AGM.  The float charge for AGM should be 2.25 to 2.30.

AGM's can be charge at a higher rate.  AGM's can be discharged up to 80% - lead acid only 50%. AGM's stand up better in colder weather.

It AGM's  'worth' 30% more  I don't know.  I'm happy with my AGM's.  If and when they fail (as all batteries do) I'll replace them with new AGM's.   Maybe with Lithium batteries fi the price is within the ball park of AGM's.

 glen google.com/+grhafford

 
Re: Lithium batteries at change out time
Reply #28
Yahoo Message Number: 156608
What I meant by early failure of AGM's is after a couple years or in some cases sooner. They seem very vulnerable to overcharging. Most folks I have talked with get about 5 years or more from the Trojans. I see them as a cost effective solution if you don't need more than 2 batteries, or if you have a way to install more on the outside of the rig like Larry has done. But each to their own and use what's best for you. It will be interesting to see what kind of life I get out of the AGM Optima I gave Larry to install in my Jeep.

I am also a fan of the Blue Sky solar controller with remote display. AM Solar doesn't sell junk, and the tech support is great. They spent an hour fixing a problem I had created with my solar display, and didn't charge me a cent. A reputable outfit.

bobmoore14